How many drinks per guest? A party planner with an alcohol-free share

Most hosts guess how many drinks to buy and end up with too much of the strong stuff and too little of everything else. A simple caterer's rule gets you close: two drinks per guest in the first hour, then one an hour.

Put in your guest count, the length of the party and how much of it should be alcohol-free, and the planner turns that into bottles, litres and water, with a 10% buffer. It also shows why the alcohol-free share is the number hosts forget.